rp: use rp2040-boot2 to provide the boot2 blob

we're currently shipping an old boot2 that runs the flash at half speed.
use the more recent version instead, and allow user to choose between
the different supported boot2 versions for different flash chips if they
need that.

embassy-rp/Cargo.toml

@@ -30,6 +30,15 @@ rom-func-cache = []
 intrinsics = []
 rom-v2-intrinsics = []
 
+# boot2 flash chip support. if none of these is enabled we'll default to w25q080 (used on the pico)
+boot2-at25sf128a = []
+boot2-gd25q64cs = []
+boot2-generic-03h = []
+boot2-is25lp080 = []
+boot2-ram-memcpy = []
+boot2-w25q080 = []
+boot2-w25x10cl = []
+
 # Enable nightly-only features
 nightly = ["embassy-executor/nightly", "embedded-hal-1", "embedded-hal-async", "embassy-embedded-hal/nightly", "dep:embassy-usb-driver", "dep:embedded-io"]
 
@@ -71,3 +80,4 @@ embedded-hal-nb = { version = "=1.0.0-alpha.2", optional = true}
 paste = "1.0"
 pio-proc = {version= "0.2" }
 pio = {version= "0.2.1" }
+rp2040-boot2 = "0.3"

embassy-rp/src/lib.rs

@@ -131,9 +131,32 @@ embassy_hal_common::peripherals! {
     WATCHDOG,
 }
 
-#[link_section = ".boot2"]
-#[used]
-static BOOT2: [u8; 256] = *include_bytes!("boot2.bin");
+macro_rules! select_bootloader {
+    ( $( $feature:literal => $loader:ident, )+ default => $default:ident ) => {
+        $(
+            #[cfg(feature = $feature)]
+            #[link_section = ".boot2"]
+            #[used]
+            static BOOT2: [u8; 256] = rp2040_boot2::$loader;
+        )*
+
+        #[cfg(not(any( $( feature = $feature),* )))]
+        #[link_section = ".boot2"]
+        #[used]
+        static BOOT2: [u8; 256] = rp2040_boot2::$default;
+    }
+}
+
+select_bootloader! {
+    "boot2-at25sf128a" => BOOT_LOADER_AT25SF128A,
+    "boot2-gd25q64cs" => BOOT_LOADER_GD25Q64CS,
+    "boot2-generic-03h" => BOOT_LOADER_GENERIC_03H,
+    "boot2-is25lp080" => BOOT_LOADER_IS25LP080,
+    "boot2-ram-memcpy" => BOOT_LOADER_RAM_MEMCPY,
+    "boot2-w25q080" => BOOT_LOADER_W25Q080,
+    "boot2-w25x10cl" => BOOT_LOADER_W25X10CL,
+    default => BOOT_LOADER_W25Q080
+}
 
 pub mod config {
     #[non_exhaustive]